On the 16th of July, 1799, at break of day, we beheld a verdant coast, of picturesque aspect. The mountains of New Andalusia, half-veiled by mists, bounded the horizon to the south. The city of Cumana and its castle appeared between groups of cocoa-trees. We anchored in the port about nine in the morning, forty-one days after our departure from Corunna; the sick dragged themselves on deck to enjoy the sight of a land which was to put an end to their sufferings. Our eyes were fixed on the groups of cocoa-trees which border the river: their trunks, more than sixty feet high, towered over every object in the landscape. The plain was covered with the tufts of Cassia, Caper, and those arborescent mimosas, which, like the pine of Italy, spread their branches in the form of an umbrella. The pinnated leaves of the palms were conspicuous on the azure sky, the clearness of which was unsullied by any trace of vapour. The sun was ascending rapidly toward the zenith. A dazzling light was spread through the air, along the whitish hills strewed with cylindric cactuses, and over a sea ever calm, the shores of which were peopled with alcatras,* egrets, and flamingoes. The splendour of the day, the vivid colouring of the vegetable world, the forms of the plants, the varied plumage of the birds, everything was stamped with the grand character of nature in the equinoctial regions.
[* A brown pelican, of the size of a swan. (Pelicanus fuscus, Linn.)]
The city of Cumana, the capital of New Andalusia, is a mile distant from the embarcadero, or the battery of the Boca, where we landed, after having passed the bar of the Manzanares. We had to cross a vast plain, called el Salado, which divides the suburb of the Guayquerias from the sea-coast. The excessive heat of the atmosphere was augmented by the reverberation of the soil, partly destitute of vegetation. The centigrade thermometer, plunged into the white sand, rose to 37.7°. In the small pools of salt water it kept at 30.5°, while the heat of the ocean, at its surface, is generally, in the port of Cumana, from 25.2 to 26.3°. The first plant we gathered on the continent of America was the Avicennia tomentosa,8 which in this place scarcely reaches two feet in height. This shrub, together with the sesuvium, the yellow gomphrena, and the cactus, cover soil impregnated with muriate of soda; they belong to that small number of plants which live in society like the heath of Europe, and which in the torrid zone are found only on the seashore, and on the elevated plains of the Andes.* The Avicennia of Cumana is distinguished by another peculiarity not less remarkable: it furnishes an instance of a plant common to the shores of South America and the coasts of Malabar.
[* Mangle prieto.]
[* On the extreme rarity of the social plants in the tropics, see my Essay on the Geog. of Plants page 19; and a paper by Mr. Brown on the Proteacea, Transactions of the Lin. Soc. volume 10 page 1, page 23, in which that great botanist has extended and confirmed by numerous facts my ideas on the association of plants of the same species.]
The Indian pilot led us across his garden, which rather resembled a copse than a piece of cultivated ground. He showed us, as a proof of the fertility of this climate, a silk-cotton tree (Bombax heptaphyllum), the trunk of which, in its fourth year, had reached nearly two feet and a half in diameter. We have observed, on the banks of the Orinoco and the river Magdalena, that the bombax, the carolinea, the ochroma, and other trees of the family of the malvaceae, are of extremely rapid growth. I nevertheless think that there was some exaggeration in the report of the Indian respecting the age of his bombax; for under the temperate zone, in the hot and damp lands of North America, between the Mississippi and the Alleghany mountains, the trees do not exceed a foot in diameter, in ten years. Vegetation in those parts is in general but a fifth more speedy than in Europe, even taking as an example the Platanus occidentalis, the tulip tree, and the Cupressus disticha, which reach from nine to fifteen feet in diameter. On the strand of Cumana, in the garden of the Guayqueria pilot, we saw for the first time a guama* loaded with flowers, and remarkable for the extreme length and silvery splendour of its numerous stamina. We crossed the suburb of the Guayqueria Indians, the streets of which are very regular, and formed of small houses, quite new, and of a pleasing appearance. This part of the town had just been rebuilt, for the earthquake had laid Cumana in ruins eighteen months before our arrival. By a wooden bridge, we crossed the river Manzanares, which contains a few bavas, or crocodiles of the smaller species.
[* Inga spuria, which we must not confound with the common inga, Inga vera, Willd. (Mimosa Inga, Linn.). The white stamina, which, to the number of sixty or seventy, are attached to a greenish corolla, have a silky lustre, and are terminated by a yellow anther. The flower of the guama is eighteen lines long. The common height of this fine tree, which prefers a moist soil, is from eight to ten toises.]
We were conducted by the captain of the Pizarro to the governor of the province, Don Vincente Emparan, to present to him the passports furnished to us by the first Secretary of State at Madrid. He received us with that frankness and unaffected dignity which have at all times characterized the natives of Biscay. Before he was appointed governor of Portobello and Cumana, Don Vincente Emparan had distinguished himself as captain of a vessel in the navy. His name recalls to mind one of the most extraordinary and distressing events recorded in the history of maritime warfare. At the time of the last rupture between Spain and England, two brothers of Senor Emperan, both of whom commanded ships in the Spanish navy, engaged with each other before the port of Cadiz, each supposing that he was attacking an enemy. A fierce battle was kept up during a whole night, and both the vessels were sunk almost simultaneously. A very small part of the crew was saved, and the two brothers had the misfortune to recognize each other a little before they expired.
The governor of Cumana expressed his great satisfaction at the resolution we had taken to remain for some time in New Andalusia, a province which at that period was but little known even by name in Europe, and which in its mountains, and on the banks of its numerous rivers, contains a great number of objects worthy of fixing the attention of naturalists. Senor Emperan showed us cottons dyed with native plants, and fine furniture made exclusively of the wood of the country. He was much interested in everything that related to natural philosophy; and asked, to our great astonishment, whether we thought, that, under the beautiful sky of the tropics, the atmosphere contained less azote (azotico) than in Spain; or whether the rapidity with which iron oxidates in those climates, were only the effect of greater humidity as indicated by the air hygrometer. The name of his native country pronounced on a distant shore would not have been more agreeable to the ear of a traveller, than those words azote, oxide of iron, and hygrometer, were to ours. Senor Emparan was a lover of science, and the public marks of consideration which he gave us during a long abode in his government, contributed greatly to procure us a favourable welcome in every part of South America.
We hired a spacious house, the situation of which was favourable for astronomical observations. We enjoyed an agreeable coolness when the breeze arose; the windows were without glass, and even without those paper panes which are often substituted for glass at Cumana. The whole of the passengers of the Pizarro left the vessel, but the recovery of those who had been attacked by the fever was very slow. We saw some who, a month after, notwithstanding the care bestowed on them by their countrymen, were still extremely weak and reduced. Hospitality, in the Spanish colonies, is such, that a European who arrives, without recommendation or pecuniary means, is almost sure of finding assistance, if he land in any port on account of sickness. The Catalonians, the Galicians, and the Biscayans, have the most frequent intercourse with America. They there form as it were three distinct corporations, which exercise a remarkable influence over the morals, the industry, and commerce of the colonies. The poorest inhabitant of Siges or Vigo is sure of being received into the house of a Catalonian or Galician pulpero,* whether he land in Chile or the Philippine Islands.
[* A retail dealer.]
Among the sick who landed at Cumana was a negro, who fell into a state of insanity a few days after our arrival; he died in that deplorable condition, though his master, almost seventy years old, who had left Europe to settle at San Blas, at the entrance of the gulf of California, had attended him with the greatest care. I relate this fact as affording evidence that men born under the torrid zone, after having dwelt in temperate climates, sometimes feel the pernicious effects of the heat of the tropics. The negro was a young man, eighteen years of age, very robust, and born on the coast of Guinea; an abode of some years on the high plain of Castile, had imparted to his organization that kind of irritability which renders the miasma of the torrid zone so dangerous to the inhabitants of the countries of the north.
The site on which Cumana is built is part of a tract of ground, very remarkable in a geological point of view. The chain of the calcareous Alps of the Brigantine and the Tataraqual stretches east and west from the summit of the Imposible to the port of Mochima and to Campanario. The sea, in times far remote, appears to have divided this chain from the rocky coasts of Araya and Maniquarez. The vast gulf of Cariaco has been caused by an irruption of the sea; and no doubt can be entertained but that the waters once covered, on the southern bank, the whole tract of land impregnated with muriate of soda, through which flows the Manzanares. The slow retreat of the waters has turned into dry ground this extensive plain, in which rises a group of small hills, composed of gypsum and calcareous breccias of very recent formation. The city of Cumana is backed by this group, which was formerly an island of the gulf of Cariaco. That part of the plain which is north of the city, is called Plaga Chica, or the Little Plain, and extends eastwards as far as Punta Delgada, where a narrow valley, covered with yellow gomphrena, still marks the point of the ancient outlet of the waters.
The hill of calcareous breccias, which we have just mentioned as having once been an island in the ancient gulf, is covered with a thick forest of cylindric cactus and opuntia. Some of these trees, thirty or forty feet high, are covered with lichens, and are divided into several branches in the form of candelabra. Near Maniquarez, at Punta Araya, we measured a cactus,* the trunk of which was four feet nine inches in circumference. A European acquainted only with the opuntia in our hot-houses is surprised to see the wood of this plant become so hard from age, that it resists for centuries both air and moisture: the Indians of Cumana therefore employ it in preference to any other for oars and door-posts. Cumana, Coro, the island of Margareta, and Curassao, are the parts of South America that abound most in plants of the nopal family. There only, a botanist, after a long residence, could compose a monography of the genus cactus, the species of which vary not only in their flowers and fruits, but also in the form of their articulated stems, the number of costae, and the disposition of the thorns. We shall see hereafter how these plants, which characterize a warm and singularly dry climate, like that of Egypt and California, gradually disappear in proportion as we remove from the coasts, and penetrate into the inland country.
[* Tuna macho. We distinguish in the wood of the cactus the medullary prolongations, as M. Desfontaines has already observed.]
The groups of columnar cactus and opuntia produce the same effect in the arid lands of equinoctial America as the junceae and the hydrocharides in the marshes of our northern climes. Places in which the larger species of the strong cactus are collected in groups are considered as almost impenetrable. These places are called Tunales; and they are impervious not only to the native, who goes naked to the waist, but are formidable even to those who are fully clothed. In our solitary rambles we sometimes endeavoured to penetrate into the Tunal that crowns the summit of the castle hill, a part of which is crossed by a pathway, where we could have studied, amidst thousands of specimens, the organization of this singular plant. Sometimes night suddenly overtook us, for there is scarcely any twilight in this climate; and we then found ourselves dangerously situated, as the Cascabel, or rattle-snake, the Coral, and other vipers armed with poisonous fangs, frequent these scorched and arid haunts, to deposit their eggs in the sand.
The castle of San Antonio is built at the western extremity of the hill, but not on the most elevated point, being commanded on the east by an unfortified summit. The Tunal is considered both here and everywhere in the Spanish colonies as a very important means of military defence; and when earthen works are raised, the engineers are eager to propagate the thorny opuntia, and promote its growth, as they are careful to keep crocodiles in the ditches of fortified places. In regions where organized nature is so powerful and active, man summons as auxiliaries in his defence the carnivorous reptile, and the plant with its formidable armour of thorns.
The castle is only thirty toises above the level of the water in the gulf of Cariaco. Standing on a naked and calcareous hill, it commands the town, and has a very picturesque effect when viewed from a vessel entering the port. It forms a bright object against the dark curtains of those mountains which raise their summits to the clouds, and of which the vaporous and bluish tint blends with the azure sky. On descending from Fort San Antonio to the south-west, we find on the slope of the same rock the ruins of the old castle of Santa Maria. This site is delightful to those who wish to enjoy at the approach of sunset the freshness of the breeze and the view of the gulf. The lofty summits of the island of Margareta are seen above the rocky coast of the isthmus of Araya, and towards the west the small islands of Caracas, Picuita, and Boracha, recall to mind the catastrophes that have overwhelmed the coasts of Terra Firma. These islets resemble fortifications, and from the effect of the mirage (while the inferior strata of the air, the ocean, and the soil, are unequally heated by the sun), their points appear raised like the extremity of the great promontories of the coast. It is pleasing, during the day, to observe these inconstant phenomena; we see, as night approaches, these stony masses which had been suspended in the air, settle down on their bases; and the luminary, whose presence vivifies organic nature, seems by the variable inflection of its rays to impress motion on the stable rock, and give an undulating movement to plains covered with arid sands.*
[* The real cause of the mirage, or the extraordinary refraction which the rays undergo when strata of air of different densities lie over each other, was guessed at by Hooke. — See his Posthumous Works page 472.]
The town of Cumana, properly so called, occupies the ground lying between the castle of San Antonio and the small rivers of Manzanares and Santa Catalina. The Delta, formed by the bifurcation of the first of these rivers, is a fertile plain covered with Mammees, Sapotas (achras), plantains, and other plants cultivated in the gardens or charas of the Indians. The town has no remarkable edifice, and the frequency of earthquakes forbids such embellishments. It is true, that strong shocks occur less frequently in a given time at Cumana than at Quito, where we nevertheless find sumptuous and very lofty churches. But the earthquakes of Quito are violent only in appearance, and, from the peculiar nature of the motion and of the ground, no edifice there is overthrown. At Cumana, as well as at Lima, and in several cities situated far from the mouths of burning volcanoes, it happens that the series of slight shocks is interrupted after a long course of years by great catastrophes, resembling the effects of the explosion of a mine. We shall have occasion to return to this phenomenon, for the explanation of which so many vain theories have been imagined, and which have been classified according to perpendicular and horizontal movements, shock, and oscillation.*
[* This classification dates from the time of Posidonius. It is the successio and inclinatio of Seneca; but the ancients had already judiciously remarked, that the nature of these shocks is too variable to permit any subjection to these imaginary laws.]
The suburbs of Cumana are almost as populous as the ancient town. They are three in number:— Serritos, on the road to the Plaga Chicha, where we meet with some fine tamarind trees; St. Francis, towards the south-east; and the great suburb of the Guayquerias, or Guayguerias. The name of this tribe of Indians was quite unknown before the conquest. The natives who bear that name formerly belonged to the nation of the Guaraounos, of which we find remains only in the swampy lands of the branches of the Orinoco. Old men have assured me that the language of their ancestors was a dialect of the Guaraouno; but that for a century past no native of that tribe at Cumana, or in the island of Margareta, has spoken any other language than Castilian.
The denomination Guayqueria, like the words Peru and Peruvian, owes its origin to a mere mistake. The companions of Christopher Columbus, coasting along the island of Margareta, the northern coast of which is still inhabited by the noblest portion of the Guayqueria nation,* encountered a few natives who were harpooning fish by throwing a pole tied to a cord, and terminating in an extremely sharp point. They asked them in the Haiti language their name; and the Indians, thinking that the question of the strangers related to their harpoons, which were formed of the hard and heavy wood of the Macana palm, answered guaike, guaike, which signifies pointed pole. A striking difference at present exists between the Guayquerias, a civilized tribe of skilled fishermen, and those savage Guaraounos of the Orinoco, who suspend their habitations on the trunks of the Moriche palm. The population of Cumana has been singularly exaggerated, but according to the most authentic registers it does not exceed 16,000 souls.
[* The Guayquerias of La Banda del Norte consider themselves as the most noble race, because they think they are less mixed with the Chayma Indian, and other copper-coloured races. They are distinguished from the Guayquerias of the continent by their manner of pronouncing the Spanish language, which they speak almost without separating their teeth. They show with pride to Europeans the Punta de la Galera, or Galley’s Point, (so called on account of the vessel of Columbus having anchored there), and the port of Manzanillo, where they first swore to the whites in 1498, that friendship which they have never betrayed, and which has obtained for them, in court phraseology, the title of fieles, loyal. — See above.]
Probably the Indian suburb will by degrees extend as far as the Embarcadero; the plain, which is not yet covered with houses or huts, being more than 340 toises in length. The heat is somewhat less oppressive on the side near the seashore, than in the old town, where the reverberation of the calcareous soil, and the proximity of the mountain of San Antonio, raise the temperature to an excessive degree. In the suburb of the Guayquerias, the sea breezes have free access; the soil is clayey, and, for that reason, it is thought to be less exposed to violent shocks of earthquake, than the houses at the foot of the rocks and hills on the right bank of the Manzanares.
The shore near the mouth of the small river Santa Catalina is bordered with mangrove trees,* but these mangroves are not sufficiently spread to diminish the salubrity of the air of Cumana. The soil of the plain is in part destitute of vegetation, in part covered with tufts of Sesuvium portulacastrum, Gomphrena flava, G. myrtifolia, Talinum cuspidatum, T. cumanense, and Portulaca lanuginosa. Among these herbaceous plants we find at intervals the Avicennia tomentosa, the Scoparia dulcis, a frutescent mimosa with very irritable leaves,* and particularly cassias, the number of which is so great in South America, that we collected, in our travels, more than thirty new species.
[* Rhizophora mangle. M. Bonpland found on the Plaga Chica the Allionia incarnata, in the same place where the unfortunate Loefling had discovered this new genus of Nyctagineae.]
[* The Spaniards designate by the name of dormideras (sleeping plants), the small number of mimosas with irritable leaves. We have increased this number by three species previously unknown to botanists, namely, the Mimosa humilis of Cumana, the M. pellita of the savannahs of Calabozo, and the M. dormiens of the banks of the Apure.]
On leaving the Indian suburb, and ascending the river southward, we found a grove of cactus, a delightful spot, shaded by tamarinds, brazilettos, bombax, and other plants, remarkable for their leaves and flowers. The soil here is rich in pasturage, and dairy-houses built with reeds, are separated from each other by clumps of trees. The milk remains fresh, when kept, not in the calabashes* of very thick ligneous fibres, but in porous earthen vessels from Maniquarez. A prejudice prevalent in northern countries had long led me to believe, that cows, under the torrid zone, did not yield rich milk; but my abode at Cumana, and especially an excursion through the vast plains of Calabozo, covered with grasses, and herbaceous sensitive plants, convinced me that the ruminating animals of Europe become perfectly habituated to the hottest climates, provided they find water and good nourishment. Milk is excellent in the provinces of New Andalusia, Barcelona, and Venezuela; and butter is better in the plains of the equinoctial zone, than on the ridge of the Andes, where the Alpine plants, enjoying in no season a sufficiently high temperature, are less aromatic than on the Pyrenees, on the mountains of Estremadura, or of Greece. As the inhabitants of Cumana prefer the coolness of the sea breeze to the sight of vegetation, their favourite walk is the open shore. The Spaniards, who in general have no great predilection for trees, or for the warbling of birds, have transported their tastes and their habits into the colonies. In Terra Firma, Mexico, and Peru, it is rare to see a native plant a tree, merely with the view of procuring shade; and if we except the environs of the great capitals, walks bordered with trees are almost unknown in those countries. The arid plain of Cumana exhibits after violent showers an extraordinary phenomenon. The earth, when drenched with rain, and heated again by the rays of the sun, emits that musky odour which in the torrid zone, is common to animals of very different classes, namely: to the jaguar, the small species of tiger cat, the cabiai or thick-nosed tapir,* the galinazo vulture,* the crocodile, the viper, and the rattlesnake. The gaseous emanations, which are the vehicles of this aroma, seem to be evolved in proportion only as the mould, containing the spoils of an innumerable quantity of reptiles, worms, and insects, begins to be impregnated with water. I have seen Indian children, of the tribe of the Chaymas, draw out from the earth and eat millipedes or scolopendras* eighteen inches long, and seven lines broad. Whenever the soil is turned up, we are struck with the mass of organic substances, which by turns are developed, transformed, and decomposed. Nature in these climates appears more active, more fruitful, we may even say more prodigal, of life.
[* These calabashes are made from the fruit of the Crescentia cujete.]
[* Cavia capybara, Linn.; chiguire.]
[* Vultur aura, Linn., Zamuro, or Galinazo: the Brazilian vulture of Buffon. I cannot reconcile myself to the adoption of names, which designate, as belonging to a single country, animals common to a whole continent.]
[* Scolopendras are very common behind the castle of San Antonio, on the summit of the hill.]
On this shore, and near the dairies just mentioned, we enjoy, especially at sunrise, a very beautiful prospect over an elevated group of calcareous mountains. As this group subtends an angle of three degrees only at the house where we dwelt, it long served me to compare the variations of the terrestrial refraction with the meteorological phenomena. Storms are formed in the centre of this Cordillera; and we see from afar thick clouds resolve into abundant rains, while during seven or eight months not a drop of water falls at Cumana. The Brigantine, which is the highest part of this chain, raises itself in a very picturesque manner behind Brito and Tataraqual. It takes its name from the form of a very deep valley on the northern declivity, which resembles the interior of a ship. The summit of this mountain is almost bare of vegetation, and is flat like that of Mowna Roa, in the Sandwich Islands. It is a perpendicular wall, or, to use a more expressive term of the Spanish navigators, a table (mesa). This peculiar form, and the symmetrical arrangement of a few cones which surround the Brigantine, made me at first think that this group, which is wholly calcareous, contained rocks of basaltic or trappean formation.
The governor of Cumana sent, in 1797, a band of determined men to explore this entirely desert country, and to open a direct road to New Barcelona, by the summit of the Mesa. It was reasonably expected that this way would be shorter, and less dangerous to the health of travellers, than the route taken by the couriers along the coasts; but every attempt to cross the chain of the mountains of the Brigantine was fruitless. In this part of America, as in Australia* to the west of Sydney, it is not so much the height of the mountain chains, as the form of the rocks, that presents obstacles difficult to surmount.
[* The Blue Mountains of Australia, and those of Carmarthen and Lansdowne, are not visible, in clear weather, beyond fifty miles. — Peron, Voyage aux Terres Australes page 389. Supposing the angle of altitude half a degree, the absolute height of these mountains would be about 620 toises.]
The longitudinal valley formed by the lofty mountains of the interior and the southern declivity of the Cerro de San Antonio, is intersected by the Rio Manzanares. This plain, the only thoroughly wooded part in the environs of Cumana, is called the Plain of the Charas,* on account of the numerous plantations which the inhabitants have begun, for some years past, along the river. A narrow path leads from the hill of San Francisco across the forest to the hospital of the Capuchins, a very agreeable country-house, which the Aragonese monks have built as a retreat for old infirm missionaries, who can no longer fulfil the duties of their ministry. As we advance to the west, the trees of the forest become more vigorous, and we meet with a few monkeys,* which, however, are very rare in the environs of Cumana. At the foot of the capparis, the bauhinia, and the zygophyllum with flowers of a golden yellow, there extends a carpet of Bromelia,* akin to the B. karatas, which from the odour and coolness of its foliage attracts the rattlesnake.
[* Chacra, by corruption chara, signifies a hut or cottage surrounded by a garden. The word ipure has the same signification.]
[* The common machi, or weeping monkey.]
[* Chihuchihue, of the family of the ananas.]
The waters of the Manzanares are very limpid in quality, and this river has no resemblance to the Manzanares of Madrid, which appears the more magnificent in contrast with the fine bridge by which it is crossed. It takes its source, like all the rivers of New Andalusia, in the savannahs (llanos) known by the names of the plateaux of Jonoro, Amana, and Guanipa,* and it receives, near the Indian village of San Fernando, the waters of the Rio Juanillo. It has been several times proposed to the government, but without success, to construct a dyke at the first ipure, in order to form artificial irrigations in the plain of Charas; for, notwithstanding its apparent sterility, the soil is extremely productive, wherever humidity is combined with the heat of the climate. The cultivators were gradually to refund the money advanced for the construction of the sluices. Meanwhile, pumps worked by mules, and other hydraulic but imperfect machines, have been erected, to serve till this project is carried into execution.
[* These three eminences bear the names of mesas, tables. An immense plain has an almost imperceptible rise from both sides to the middle, without any appearance of mountains or hills.]
The banks of the Manzanares are very pleasant, and are shaded by mimosas, erythrinas, ceibas, and other trees of gigantic growth. A river, the temperature of which, in the season of the floods, descends as low as twenty-two degrees, when the air is at thirty and thirty-three degrees, is an inestimable benefit in a country where the heat is excessive during the whole year, and where it is so agreeable to bathe several times in the day. The children pass a considerable part of their lives in the water; all the inhabitants, even the women of the most opulent families, know how to swim; and in a country where man is so near the state of nature, one of the first questions asked on meeting in the morning is, whether the water is cooler than it was on the preceding evening. One of the modes of bathing is curious. We every evening visited a family, in the suburb of the Guayquerias. In a fine moonlight night, chairs were placed in the water; the men and women were lightly clothed, as in some baths of the north of Europe; and the family and strangers, assembled in the river, passed some hours in smoking cigars, and in talking, according to the custom of the country, of the extreme dryness of the season, of the abundant rains in the neighbouring districts, and particularly of the extravagancies of which the ladies of Cumana accuse those of Caracas and the Havannah. The company were under no apprehensions from the bavas, or small crocodiles, which are now extremely scarce, and which approach men without attacking them. These animals are three or four feet long. We never met with them in the Manzanares, but with a great number of dolphins (toninas), which sometimes ascend the river in the night, and frighten the bathers by spouting water.
The port of Cumana is a roadstead capable of receiving the fleets of Europe. The whole of the Gulf of Cariaco, which is about 35 miles long and 48 broad, affords excellent anchorage. The Pacific is not more calm on the shores of Peru, than the Caribbean Sea from Porto-cabello, and especially from Cape Codera to the point of Paria. The hurricanes of the West Indies are never felt in these regions. The only danger in the port of Cumana is a shoal, called Morro Roxo. There are from one to three fathoms water on this shoal, while just beyond its edges there are eighteen, thirty, and even thirty-eight. The remains of an old battery, situated north-north-east of the castle of San Antonio, and very near it, serve as a mark to avoid the bank of Morro Roxo.
The city lies at the foot of a hill destitute of verdure, and is commanded by a castle. No steeple or dome attracts from afar the eye of the traveller, but only a few trunks of tamarind, cocoa, and date trees, which rise above the houses, the roofs of which are flat. The surrounding plains, especially those on the coasts, wear a melancholy, dusty, and arid appearance, while a fresh and luxuriant vegetation marks from afar the windings of the river, which separates the city from the suburbs; the population of European and mixed race from the copper-coloured natives. The hill of fort San Antonio, solitary, white, and bare, reflects a great mass of light, and of radiant heat: it is composed of breccia, the strata of which contain numerous fossils. In the distance, towards the south, stretches a vast and gloomy curtain of mountains. These are the high calcareous Alps of New Andalusia, surmounted by sandstone, and other more recent formations. Majestic forests cover this Cordillera of the interior, and they are joined by a woody vale to the open clayey lands and salt marshes of the environs of Cumana. A few birds of considerable size contribute to give a peculiar character to these countries. On the seashore, and in the gulf, we find flocks of fishing herons, and alcatras of a very unwieldy form, which swim, like the swan, raising their wings. Nearer the habitation of man, thousands of galinazo vultures, the jackals of the winged tribe, are ever busy in disinterring the carcases of animals.* A gulf, containing hot and submarine springs, divides the secondary from the primary and schistose rocks of the peninsula of Araya. Each of these coasts is washed by a tranquil sea, of azure tint, and always gently agitated by a breeze from one quarter. A bright clear sky, with a few light clouds at sunset, reposes on the ocean, on the treeless peninsula, and on the plains of Cumana, while we see the storms accumulate and descend in fertile showers among the inland mountains. Thus on these coasts, as well as at the foot of the Andes, the earth and the sky present the extremes of clear weather and fogs, of drought and torrents of rain, of absolute nudity and never-ceasing verdure.
[* Buffon Hist. Nat. des Oiseaux tome 1 page 114.]
The analogies which we have just indicated, between the sea-coasts of New Andalusia and those of Peru, extend also to the recurrence of earthquakes, and the limits which nature seems to have prescribed to these phenomena. We have ourselves felt very violent shocks at Cumana; and we learned on the spot, the most minute circumstances that accompanied the great catastrophe of the 14th December, 1797.
It is a very generally received opinion on the coasts of Cumana, and in the island of Margareta, that the gulf of Cariaco owes its existence to a rent of the continent attended by an irruption of the sea. The remembrance of that great event was preserved among the Indians to the end of the fifteenth century; and it is related that, at the time of the third voyage of Christopher Columbus, the natives mentioned it as of very recent date. In 1530, the inhabitants were alarmed by new shocks on the coasts of Paria and Cumana. The land was inundated by the sea, and the small fort, built by James Castellon at New Toledo,* was entirely destroyed. At the same time an enormous opening was formed in the mountains of Cariaco, on the shores of the gulf bearing that name, when a great body of salt-water, mixed with asphaltum, issued from the micaceous schist. Earthquakes were very frequent about the end of the sixteenth century; and, according to the traditions preserved at Cumana, the sea often inundated the shores, rising from fifteen to twenty fathoms.
[* This was the first name given to the city of Cumana — Girolamo Benzoni Hist. del Mondo Nuovo pages 3, 31, and 33. James Castellon arrived at St. Domingo in 1521, after the appearance of the celebrated Bartholomew de las Casas in these countries. On attentively reading the narratives of Benzoni and Caulin, we find that the fort of Castellon was built near the mouth of the Manzanares (alla ripa del fiume de Cumana); and not, as some modern travellers have asserted, on the mountain where now stands the castle of San Antonio.]
As no record exists at Cumana, and its archives, owing to the continual devastations of the termites, or white ants, contain no document that goes back farther than a hundred and fifty years, we are unacquainted with the precise dates of the ancient earthquakes. We only know, that, in times nearer our own, the year 1776 was at once the most fatal to the colonists, and the most remarkable for the physical history of the country. The city of Cumana was entirely destroyed, the houses were overturned in the space of a few minutes, and the shocks were hourly repeated during fourteen months. In several parts of the province the earth opened, and threw out sulphureous waters. These irruptions were very frequent in a plain extending towards Casanay, two leagues east of the town of Cariaco, and known by the name of the hollow ground (tierra hueca), because it appears entirely undermined by thermal springs. During the years 1766 and 1767, the inhabitants of Cumana encamped in their streets; and they began to rebuild their houses only when the earthquakes recurred once a month. What was felt at Quito, immediately after the great catastrophe of February 1797, took place on these coasts. While the ground was in a state of continual oscillation, the atmosphere seemed to dissolve itself into water.
Tradition states that in the earthquake of 1766, as well as in another remarkable one in 1794, the shocks were mere horizontal oscillations; it was only on the disastrous 14th of December, 1797, that for the first time at Cumana the motion was felt by an upheaving of the ground. More than four-fifths of the city were then entirely destroyed; and the shock, attended by a very loud subterraneous noise, resembled, as at Riobamba, the explosion of a mine at a great depth. Happily the most violent shock was preceded by a slight undulating motion, so that most of the inhabitants were enabled to escape into the streets, and a small number only perished of those who had assembled in the churches. It is a generally received opinion at Cumana, that the most destructive earthquakes are announced by very feeble oscillations, and by a hollow sound, which does not escape the observation of persons habituated to this kind of phenomenon. In those fatal moments the cries of ‘misericordia! tembla! tembla!’* are everywhere heard; and it rarely happens that a false alarm is given by a native. Those who are most apprehensive attentively observe the motions of dogs, goats, and swine. The last-mentioned animals, endowed with delicate olfactory nerves, and accustomed to turn up the earth, give warning of approaching danger by their restlessness and their cries. We shall not attempt to decide, whether, being nearer the surface of the ground, they are the first to hear the subterraneous noise; or whether their organs receive the impression of some gaseous emanation which issues from the earth. We cannot deny the possibility of this latter cause. During my abode at Peru, a fact was observed in the inland country, which has an analogy with this kind of phenomenon, and which is not unfrequent. At the end of violent earthquakes, the herbs that cover the savannahs of Tucuman acquired noxious properties; an epidemic disorder broke out among the cattle, and a great number of them appeared stupified or suffocated by the deleterious vapours exhaled from the ground.
[* “Mercy! the earthquake! the earthquake!”— See Tschudi’s Travels in Peru page 170.]
At Cumana, half an hour before the catastrophe of the 14th of December, 1797, a strong smell of sulphur was perceived near the hill of the convent of San Francisco; and on the same spot the subterraneous noise, which seemed to proceed from south-east to north-west, was loudest. At the same time flames appeared on the banks of the Manzanares, near the hospital of the Capuchins, and in the gulf of Cariaco, near Mariguitar. This last phenomenon, so extraordinary in a country not volcanic, is pretty frequent in the Alpine calcareous mountains near Cumanacoa, in the valley of Bordones, in the island of Margareta, and amidst the Llanos or savannahs of New Andalusia. In these savannahs, flakes of fire rising to a considerable height, are seen for hours together in the dryest places; and it is asserted, that, on examining the ground no crevice is perceptible. This fire, which resembles the springs of hydrogen, or Salse, of Modena, or what is called the will-o’-the-wisp of our marshes, does not burn the grass; because, no doubt, the column of gas, which develops itself, is mixed with azote and carbonic acid, and does not burn at its basis. The people, although less superstitious here than in Spain, call these reddish flames by the singular name of ‘the soul of the tyrant Aguirre;’ imagining that the spectre of Lopez Aguirre, harassed by remorse, wanders over these countries sullied by his crimes.*
[* When at Cumana, or in the island of Margareta, the people pronounce the words el tirano (the tyrant), it is always to denote the hated Lopez d’Aguirre, who, after having taken part, in 1560, in the revolt of Fernando de Guzman against Pedro de Ursua, governor of the Omeguas and Dorado, voluntarily took the title of traidor, or traitor. He descended the river Amazon with his band, and reached by a communication of the rivers of Guyana the island of Margareta. The port of Paraguache still bears, in this island, the name of the Tyrant’s Port.]
The great earthquake of 1797 produced some changes in the configuration of the shoal of Morro Roxo, towards the mouth of the Rio Bordones. Similar swellings were observed at the time of the total destruction of Cumana, in 1766. At that period, the Punta Delgado, on the southern coast of the gulf of Cariaco, became perceptibly enlarged; and in the Rio Guarapiche, near the village of Maturin, a shoal was formed, no doubt by the action of the elastic fluids, which displaced and raised up the bed of the river.
In order to follow a plan conformable to the end we proposed in this work, we shall endeavour to generalize our ideas, and to comprehend in one point of view everything that relates to these phenomena, so terrific, and so difficult to explain. If it be the duty of the men of science who visit the Alps of Switzerland, or the coasts of Lapland, to extend our knowledge respecting the glaciers and the aurora borealis, it may be expected that a traveller who has journeyed through Spanish America, should have chiefly fixed his attention on volcanoes and earthquakes. Each part of the globe is an object of particular study; and when we cannot hope to penetrate the causes of natural phenomena, we ought at least to endeavour to discover their laws, and distinguish, by the comparison of numerous facts, that which is permanent and uniform from that which is variable and accidental.
The great earthquakes, which interrupt the long series of slight shocks, appear to have no regular periods at Cumana. They have taken place at intervals of eighty, a hundred, and sometimes less than thirty years; while on the coasts of Peru, for instance at Lima, a certain regularity has marked the periods of the total destruction of the city. The belief of the inhabitants in the existence of this uniformity has a happy influence on public tranquillity, and the encouragement of industry. It is generally admitted, that it requires a sufficiently long space of time for the same causes to act with the same energy; but this reasoning is just only inasmuch as the shocks are considered as a local phenomenon; and a particular focus, under each point of the globe exposed to those great catastrophes, is admitted. Whenever new edifices are raised on the ruins of the old, we hear from those who refuse to build, that the destruction of Lisbon on the first day of November, 1755, was soon followed by a second, and not less fatal convulsion, on the 31st of March, 1761.
It is a very ancient opinion,* and one that is commonly received at Cumana, Acapulco, and Lima, that a perceptible connection exists between earthquakes and the state of the atmosphere that precedes those phenomena. But from the great number of earthquakes which I have witnessed to the north and south of the equator; on the continent, and on the seas; on the coasts, and at 2500 toises height; it appears to me that the oscillations are generally very independent of the previous state of the atmosphere. This opinion is entertained by a number of intelligent residents of the Spanish colonies, whose experience extends, if not over a greater space of the globe, at least over a greater number of years, than mine. On the contrary, in parts of Europe where earthquakes are rare compared to America, scientific observers are inclined to admit an intimate connection between the undulations of the ground, and certain meteors, which appear simultaneously with them. In Italy for instance, the sirocco and earthquakes are suspected to have some connection; and in London, the frequency of falling-stars, and those southern lights which have since been often observed by Mr. Dalton, were considered as the forerunners of those shocks which were felt from 1748 to 1756.
[* Aristotle de Meteor. lib. 2 (ed. Duval, tome 1 page 798). Seneca Nat. Quaest. lib. 6 c. 12.]
On days when the earth is shaken by violent shocks, the regularity of the horary variations of the barometer is not disturbed within the tropics. I had opportunities of verifying this observation at Cumana, at Lima, and at Riobamba; and it is the more worthy of attention, as at St. Domingo, (in the town of Cape Francois,) it is asserted, that a water-barometer sank two inches and a half immediately before the earthquake of 1770. It is also related, that, at the time of the destruction of Oran, a druggist fled with his family, because, observing accidentally, a few minutes before the earthquake, the height of the mercury in his barometer, he perceived that the column sank in an extraordinary manner. I know not whether we can give credit to this story; but as it is nearly impossible to examine the variations of the weight of the atmosphere during the shocks, we must be satisfied with observing the barometer before or after these phenomena have taken place.
We can scarcely doubt, that the earth, when opened and agitated by shocks, spreads occasionally gaseous emanations through the atmosphere, in places remote from the mouths of volcanoes not extinct. At Cumana, it has already been observed that flames and vapours mixed with sulphurous acid spring up from the most arid soil. In other parts of the same province, the earth ejects water and petroleum. At Riobamba, a muddy and inflammable mass, called moya, issues from crevices that close again, and accumulates into elevated hills. At about seven leagues from Lisbon, near Colares, during the terrible earthquake of the 1st of November, 1755, flames and a column of thick smoke were seen to issue from the flanks of the rocks of Alvidras, and, according to some witnesses, from the bosom of the sea.
Elastic fluids thrown into the atmosphere may act locally on the barometer, not by their mass, which is very small, compared to the mass of the atmosphere, but because, at the moment of great explosions, an ascending current is probably formed, which diminishes the pressure of the air. I am inclined to think that in the majority of earthquakes nothing escapes from the agitated earth; and that, when gaseous emanations and vapours are observed, they oftener accompany or follow, than precede the shocks. This circumstance would seem to explain the mysterious influence of earthquakes in equinoctial America, on the climate, and on the order of the dry and rainy seasons. If the earth generally act on the air only at the moment of the shocks, we can conceive why a sensible meteorological change so rarely precedes those great revolutions of nature.
The hypothesis according to which, in the earthquakes of Cumana, elastic fluids tend to escape from the surface of the soil, seems confirmed by the great noise which is heard during the shocks at the borders of the wells in the plain of Charas. Water and sand are sometimes thrown out twenty feet high. Similar phenomena were observed in ancient times by the inhabitants of those parts of Greece and Asia Minor abounding with caverns, crevices, and subterraneous rivers. Nature, in her uniform progress, everywhere suggests the same ideas of the causes of earthquakes, and the means by which man, forgetting the measure of his strength, pretends to diminish the effect of the subterraneous explosions. What a great Roman naturalist has said of the utility of wells and caverns* is repeated in the New World by the most ignorant Indians of Quito, when they show travellers the guaicos, or crevices of Pichincha.
[* “In puteis est remedium, quale et crebri specus praebent: conceptum enim spiritum exhalant: quod in certis notatur oppidis, quae minus quatiuntur, crebris ad eluviem cuniculis cavata.”— Pliny lib. 2 c. 82 (ed. Par. 1723 t. 1 page 112.) Even at present, in the capital of St. Domingo, wells are considered as diminishing the violence of the shocks. I may observe on this occasion, that the theory of earthquakes, given by Seneca, (Nat. Quaest. lib. 6 c. 4–31), contains the germ of everything that has been said in our times on the action of the elastic vapours confined in the interior of the globe.]
The subterranean noise, so frequent during earthquakes, is generally not in the ratio of the force of the shocks. At Cumana it constantly precedes them, while at Quito, and recently at Caracas, and in the West India Islands, a noise like the discharge of a battery was heard a long time after the shocks had ceased. A third kind of phenomenon, the most remarkable of the whole, is the rolling of those subterranean thunders, which last several months, without being accompanied by the least oscillatory motion of the ground.*
[* The subterranean thunders (bramidos y truenos subterraneos) of Guanaxuato. The phenomenon of a noise without shocks was observed by the ancients. — Aristot. Meteor. lib. 2 (ed. Duval page 802). Pliny lib. 2 c. 80.]
In every country subject to earthquakes, the point at which, probably owing to a particular disposition of the stony strata, the effects are most sensibly felt, is considered as the cause and the focus of the shocks. Thus, at Cumana, the hill of the castle of San Antonio, and particularly the eminence on which stands the convent of St. Francis, are believed to contain an enormous quantity of sulphur and other inflammable matter. We forget that the rapidity with which the undulations are propagated to great distances, even across the basin of the ocean, proves that the centre of action is very remote from the surface of the globe. From this same cause no doubt earthquakes are not confined to certain species of rocks, as some naturalists suppose, but all are fitted to propagate the movement. Keeping within the limits of my own experience I may here cite the granites of Lima and Acapulco; the gneiss of Caracas; the mica-slate of the peninsula of Araya; the primitive thonschiefer of Tepecuacuilco, in Mexico; the secondary limestones of the Apennines, Spain, and New Andalusia; and finally, the trappean porphyries of the provinces of Quito and Popayan.* In these different places the ground is frequently agitated by the most violent shocks; but sometimes, in the same rock, the superior strata form invincible obstacles to the propagation of the motion. Thus, in the mines of Saxony, we have seen workmen hasten up alarmed by oscillations which were not felt at the surface of the ground.
[* I might add to the list of secondary rocks, the gypsum of the newest formation, for instance, that of Montmartre, situated on a marine calcareous rock, which is posterior to the chalk. — See the Memoires de l’Academie tome 1 page 341 on the earthquake felt at Paris and its environs in 1681.]
If, in regions the most remote from each other, primitive, secondary, and volcanic rocks, share equally in the convulsive movements of the globe; we cannot but admit also that within a space of little extent, certain classes of rocks oppose themselves to the propagation of the shocks. At Cumana, for instance, before the great catastrophe of 1797, the earthquakes were felt only along the southern and calcareous coast of the gulf of Cariaco, as far as the town of that name; while in the peninsula of Araya, and at the village of Maniquarez, the ground did not share the same agitation. But since December 1797, new communications appear to have been opened in the interior of the globe. The peninsula of Araya is now not merely subject to the same agitations as the soil of Cumana, but the promontory of mica-slate, previously free from earthquakes, has become in its turn a central point of commotion. The earth is sometimes strongly shaken at the village of Maniquarez, when on the coast of Cumana the inhabitants enjoy the most perfect tranquillity. The gulf of Cariaco, nevertheless, is only sixty or eighty fathoms deep.
It has been thought from observations made both on the continent and in the islands, that the western and southern coasts are most exposed to shocks. This observation is connected with opinions which geologists have long formed respecting the position of the high chains of mountains, and the direction of their steepest declivities; but the existence of the Cordillera of Caracas, and the frequency of the oscillations on the eastern and northern coast of Terra Firma, in the gulf of Paria, at Carupano, at Cariaco, and at Cumana, render the accuracy of that opinion doubtful.
In New Andalusia, as well as in Chile and Peru, the shocks follow the course of the shore, and extend but little inland. This circumstance, as we shall soon find, indicates an intimate connection between the causes which produce earthquakes and volcanic eruptions. If the earth was most agitated on the coasts, because they are the lowest part of the land, why should not the oscillations be equally strong and frequent on those vast savannahs or prairies,* which are scarcely eight or ten toises above the level of the ocean?
[* The Llanos of Cumana, of New Barcelona, of Calabozo, of Apure, and of Meta.]
The earthquakes of Cumana are connected with those of the West India Islands; and it has even been suspected that they have some connection with the volcanic phenomena of the Cordilleras of the Andes. On the 4th of February 1797, the soil of the province of Quito suffered such a destructive commotion, that near 40,000 natives perished. At the same period the inhabitants of the eastern Antilles were alarmed by shocks, which continued during eight months, when the volcano of Guadaloupe threw out pumice-stones, ashes, and gusts of sulphureous vapours. The eruption of the 27th of September, during which very long-continued subterranean noises were heard, was followed on the 14th of December by the great earthquake of Cumana. Another volcano of the West India Islands, that of St. Vincent, affords an example of these extraordinary connections. This volcano had not emitted flames since 1718, when they burst forth anew in 1812. The total ruin of the city of Caracas preceded this explosion thirty-five days, and violent oscillations of the ground were felt both in the islands and on the coasts of Terra Firma.
It has long been remarked that the effects of great earthquakes extend much farther than the phenomena arising from burning volcanoes. In studying the physical revolutions of Italy, in carefully examining the series of the eruptions of Vesuvius and Etna, we can scarcely recognise, notwithstanding the proximity of these mountains, any traces of a simultaneous action. It is on the contrary beyond a doubt, that at the period of the last and preceding destruction of Lisbon,* the sea was violently agitated even as far as the New World, for instance, at the island of Barbados, more than twelve hundred leagues distant from the coasts of Portugal.
[* Destruction of Lisbon: The 1st of November, 1755, and 31st of March, 1761. During the first of these earthquakes, the sea inundated, in Europe, the coasts of Sweden, England, and Spain; in America, the islands of Antigua, Barbados, and Martinique. At Barbados, where the ordinary tides rise only from twenty-four to twenty-eight inches, the water rose twenty feet in Carlisle Bay. It became at the same time as black as ink; being, without doubt, mixed with the petroleum, or asphaltum, which abounds at the bottom of the sea, as well on the coasts of the gulf of Cariaco, as near the island of Trinidad. In the West Indies, and in several lakes of Switzerland, this extraordinary motion of the waters was observed six hours after the first shock that was felt at Lisbon — Philosophical Transactions volume 49 pages 403, 410, 544, 668; ibid. volume 53 page 424. At Cadiz a mountain of water sixty feet high was seen eight miles distant at sea. This mass threw itself impetuously on the coasts, and beat down a great number of houses; like the wave eighty-four feet high, which on the 9th of June, 1586, at the time of the great earthquake of Lima, covered the port of Callao. — Acosta Hist. Natural de las Indias edition de 1591 page 123. In North America, on Lake Ontario, violent agitations of the water were observed from the month of October 1755. These phenomena are proofs of subterraneous communications at enormous distances. On comparing the periods of the great catastrophes of Lima and Guatimala, which generally succeed each other at long intervals, it has sometimes been thought, that the effect of an action slowly propagating along the Cordilleras, sometimes from north to south, at other times from south to north, may be perceived. — Cosmo Bueno Descripcion del Peru ed. de Lima page 67. Four of these remarkable catastrophes, with their dates, may be here enumerated.
|MEXICO. (Latitude 13° 32′ north.)||PERU. (Latitude 12° 2′ south.)|
|30th of November, 1577||17th of June, 1578.|
|4th of March, 1679||17th of June, 1678.|
|12th of February, 1689||10th of October, 1688.|
|27th of September, 1717||8th of February, 1716.|
When the shocks are not simultaneous, or do not follow each other at short intervals, great doubts may be entertained with respect to the supposed communication of the movement.]
Several facts tend to prove that the causes which produce earthquakes have a near connection with those which act in volcanic eruptions. The connection of these causes was known to the ancients, and it excited fresh attention at the period of the discovery of America. The discovery of the New World not only offered new productions to the curiosity of man, it also extended the then existing stock of knowledge respecting physical geography, the varieties of the human species, and the migrations of nations. It is impossible to read the narratives of early Spanish travellers, especially that of the Jesuit Acosta, without perceiving the influence which the aspect of a great continent, the study of extraordinary appearances of nature, and intercourse with men of different races, must have exercised on the progress of knowledge in Europe. The germ of a great number of physical truths is found in the works of the sixteenth century; and that germ would have fructified, had it not been crushed by fanaticism and superstition. We learned, at Pasto, that the column of black and thick smoke, which, in 1797, issued for several months from the volcano near that shore, disappeared at the very hour, when, sixty leagues to the south, the towns of Riobamba, Hambato, and Tacunga were destroyed by an enormous shock. In the interior of a burning crater, near those hillocks formed by ejections of scoriae and ashes, the motion of the ground is felt several seconds before each partial eruption takes place. We observed this phenomenon at Vesuvius in 1805, while the mountain threw out incandescent scoriae; we were witnesses of it in 1802, on the brink of the immense crater of Pichincha, from which, nevertheless, at that time, clouds of sulphureous acid vapours only issued.
Everything in earthquakes seems to indicate the action of elastic fluids seeking an outlet to diffuse themselves in the atmosphere. Often, on the coasts of the Pacific, the action is almost instantaneously communicated from Chile to the gulf of Guayaquil, a distance of six hundred leagues; and, what is very remarkable, the shocks appear to be the stronger in proportion as the country is distant from burning volcanoes. The granitic mountains of Calabria, covered with very recent breccias, the calcareous chain of the Apennines, the country of Pignerol, the coasts of Portugal and Greece, those of Peru and Terra Firma, afford striking proofs of this fact. The globe, it may be said, is agitated with the greater force, in proportion as the surface has a smaller number of funnels communicating with the caverns of the interior. At Naples and at Messina, at the foot of Cotopaxi and of Tunguragua, earthquakes are dreaded only when vapours and flames do not issue from the craters. In the kingdom of Quito, the great catastrophe of Riobamba led several well-informed persons to think that that country would be less frequently disturbed, if the subterranean fire should break the porphyritic dome of Chimborazo; and if that colossal mountain should become a burning volcano. At all times analogous facts have led to the same hypotheses. The Greeks, who, like ourselves, attributed the oscillations of the ground to the tension of elastic fluids, cited in favour of their opinion, the total cessation of the shocks at the island of Euboea, by the opening of a crevice in the Lelantine plain.*
[* “The shocks ceased only when a crevice, which ejected a river of fiery mud, opened in the plain of Lelantum, near Chalcis.”— Strabo.]
The phenomena of volcanoes, and those of earthquakes, have been considered of late as the effects of voltaic electricity, developed by a particular disposition of heterogeneous strata. It cannot be denied, that often, when violent shocks succeed each other within the space of a few hours, the electricity of the air sensibly increases at the instant the ground is most agitated; but to explain this phenomenon, it is unnecessary to recur to an hypothesis, which is in direct contradiction to everything hitherto observed respecting the structure of our planet, and the disposition of its strata.
Last updated Tuesday, August 25, 2015 at 14:10